This invention relates to compounds containing primary amino groups attached to the molecular skeleton by urethane and/or urea groups and also hydroxyl groups and optionally isocyanate inert groups and processes for their preparation and use.
According to EP-B No. 81,701, elastic polyurethane molded products having a compact surface layer are obtained from polyethers with molecular weights of from 1800 to 12,000 in which the isocyanate reactive groups contain at least 50% primary and/or secondary amino end groups (and possibly also hydroxyl groups). The disclosed polyethers may be obtained by the pressure amination of polyether polyols or by the hydrogenation of adducts of acrylonitrile and polyether polyols or by the reaction of polyols with isatoic acid anhydride or by the hydrolysis of isocyanate compounds according to DE-A No. 2,948,419. The polyethers may also be mixed, for example, with polyether polyols to form a polyether mixture having the composition claimed. Suitable amino polyethers may also be obtained by partial pressure hydrogenation in the presence of ammonia. These aminopolyethers may contain, for example, 80 equivalent percent of amino groups and 20 equivalent percent of hydroxyl groups.
In accordance with U.S. Pat. No. 4,588,840, polyoxyalkylene-aryl polyamines may be obtained by reaction of polyoxyalkylene polyols with aromatic amines and hydrogen under pressure in the presence of catalysts containing nickel, cobalt, copper or manganese.
Amino compounds of this kind may also be obtained, for example, according to EP-A No. 0,050,275 by hydrolysis of the corresponding preliminary isocyanate stages (in particular isocyanate prepolymers). These compounds are a very suitable starting material for the preparation of polyurethane (urea) elastomers.
The higher molecular weight compounds which are particularly suitable for this purpose, however, have relatively high viscosities, e.g. in the region of 10,000 to 100,000 mPas/25.degree. C., and are therefore very difficult to process. This high viscosity is due to the fact that the preferred starting compounds for the preparation of the preferred amino compounds are isocyanate prepolymers which are obtained by the reaction of polyols (preferably polyether polyols) with excess quantities of polyisocyanates and contain urethane groups. These isocyanate prepolymers have a substantially higher viscosity than the underlying polyether polyols (generally about twice the viscosity).